What exactly is a ‘peanut ball’ is and how you can use it in birth?
Many women will discover the benefits of a traditional fitball during pregnancy – it often replaces a desk chair, can be comfortable to sit on when relaxing at home, can be used to stretch and strength the body, and gentle bouncing is often touted as a technique to initiate labour. In the same way fitballs are a common prop in pregnancy, they are regularly used to help women find comfort in labour. But how does the peanut ball, similar and at the same time quite different, work in a labour? Most commonly it is used to support women in labour who have been given an epidural or who find they need to rest. The peanut ball fits comfortably between the legs, providing support and opening the pelvis. This opening is hugely important in facilitating baby’s movement through the birth canal, and the additional support of the ball is particularly valuable when a birthing women’s movement is limited. “The peanut ball is a non-pharmacological method of pain relief that may be used by women using epidurals in labour, and preliminary randomised controlled trials in the USA have shown clinically and statistically significant findings. Currently, peanut balls are being used by women during labour, in hospitals in Australia; however, there is no existing evidence that the peanut ball makes a difference for women, either as a birthing ball or whilst using an epidural.” Stulz, V., Campbell, D., Yin, B. et al., 2018.
So how exactly do you use it? "The side lying position is when the woman is lying on her side, and the peanut ball is wedged between her legs. The top leg lays on the top of the peanut ball curve, and the bottom leg is bent underneath the peanut ball curve. The head of the bed is elevated as much as possible to ensure that the woman is comfortable.” 
“The tuck position is also a side lying position, and the legs are pulled up towards the woman’s head and the ball is brought forward towards the woman’s chest so that the woman can hug the ball with her arms. The head of the bed should also be elevated as much as possible to ensure that the woman is comfortable. This position can also be used for pushing.” 
“The semi sitting position is when the woman is sitting semi recumbent, and the top leg rests over the peanut ball over the natural curve and the bottom leg is bent and rests under the ball.” 
This video may also be useful https://www.youtube.com/watch?v=1Hwn3SctLIE
Can you get different size peanut balls?
The balls are available in a number of sizes:
45cm – Recommended for women who are under 160cms
50cm – Recommended for women who are 160cm – 170cms
60cm – Recommended for women who are 174cm or taller
Whilst large studies in Australia are yet to be done, many midwives and hospitals report excellent results when birthing mothers with epidurals are utilising the peanut ball to optimise their pelvic positioning, so may be worth considering in your birth options & preferences.
1. Stulz, V., Campbell, D., Yin, B. et al. Using a peanut ball during labour versus not using a peanut ball during labour for women using an epidural: study protocol for a randomised controlled pilot study. https://rdcu.be/b5rQF